Actually if you read my profile you'd notice I am strictly "against" selling Songs I write for God,because I feel it is "stealing from/cheating God" to accept money for something that I do for God that is only possible because of God,just like if I became a child Christian teacher at a church,I would reject money there too because both are things I like doing for God that only are fruitful because of the holy spirit,so it really feels "contradictory" because in either case to me it would feel like I'm saying to God"I faithfully try to serve you but that isn't enough I need to use your name and songs I write for you to make money,and I appreciate the holy spirit for teaching children your word but I need a salary because I don't trust you to give the increase when I work at my regular job",see for me I can't do that,after all God has done for me it wouldn't feel right to "use" his name,word,or songs he gives me for "personal gain" because they are to be for him and encouraging others to come to God,not for "personal profit",that's why I only sing my songs at churches and never ask for money for them because whatever is gained should be for God in someway,such as churches receiving donations perhaps due to the songs but ideally the money is used for God by having it used for those in need in churches or outside churches,and for spreading his word.
I know that sounds rather a harsh thing to say but it's just the way I feel about it and it's one of the few things I am not about to change my mind about.